Changes in clinical & biochemical presentations of primary hyperparathyroidism in India over a period of 20 years

BACKGROUND & OBJECTIVES: With the advent of serum chemistry autoanalyzer and routine estimation of serum calcium as a part of annual physical examination, there has been a dramatic change in the presentation of primary hyperparathyroidism (PHPT) from symptomatic to asymptomatic disease in the United States. However, such trend has not been documented from India. We carried out this retrospective study to analyse the changes in clinical presentations of PHPT patients over a period of two decades in a tertiary care centre in north India. METHODS: This retrospective study included patients with PHPT treated at a single centre of north India between March1990 and October 2010. Two decades were divided into four different time periods, i.e. 1990 to 1994, 1995 to 1999, 2000 to 2004 and 2005 to 2010. Clinical presentations, biochemical parameters and surgical outcomes were compared between different time periods using appropriate statistical methods. RESULTS: Data of 202 patients with PHPT with male: female ratio of 3:7 were analyzed. There was a rise in the number of cases of PHPT diagnosed in the last decade compared to the previous decade (28 cases vs 174 cases, P<0.001). Change in the mean age, male: female ratio, lag time for the diagnosis of PHPT and clinical presentations of PHPT (predominance of bone and stone symptoms) did not differ across different time periods. Non-significant decrease in serum calcium levels at the time of diagnosis of PHPT and a significant, decline in the serum alkaline phosphatase levels (P<0.01) were found in the last decade, however, iPTH levels were higher in the last decade (P<0.05). There was no change in the site and size of parathyroid adenoma in the two decades, however, postoperative symptomatic hypocalcemia was less frequent in the last decade. INTERPRETATION & CONCLUSIONS: The findings of this retrospective analysis show that the PHPT still remains symptomatic disease with increasing awareness over the last two decades in our center. There was not much change in the clinical presentation, in the past two decades.